Solitary sclerotic fibroma of the skin: a possible clue for Cowden syndrome

Subungual pleomorphic fibroma: a case report and review of the literature

“…The spindled cells are only mildly atypical and the random bizarre atypia seen in pleomorphic fibroma is not a feature. Benign cutaneous mesenchymal lesions exhibiting atypical spindled cells include dermatofibroma with monster cells and sclerotic fibroma [4], the latter likely defining part of a morphologic continuum with pleomorphic fibroma [5,6]. The classic subungual Koenen fibromas of tuberous sclerosis present with longitudinal ridges that can exhibit a reddish discoloration or a loss of color (i.e.…”

Circumscribed storiform collagenoma, an unusual tumor

“…The pathogenesis of CSC is still controversial. Its association with Cowden syndrome, the tendency to recurrence, the expression of cell proliferation markers such as PCNA (proliferating cell nuclear antigen) and Ki-67, and the evidence of synthesis of type I collagen support the concept that it is a fibrous tumor with active growth [4][5][6][9][10][11]. In contrast, the presence of focal areas with CSC-like changes in other neoplastic and inflammatory lesions (dermatofibroma, neurofibroma, angiofibroma, fibroma of the tendon sheath, pleomorphic fibroma, melanocytic nevi, sclerotic lipoma, giant cell collagenomas, giant cell angiohistiocytoma, erythema elevatum diutinum, or folliculitis) supports the theory that CSC is an involutional stage of a preexisting lesion or a distinctive pattern of degenerated connective tissue [1,2,12,13].…”

“…Multiple CSCs have been considered as another specific cutaneous marker of CS, as clinically useful as facial trichilemmomas [4]. In some case reports, a solitary CSC was the only clue before establishing a definitive diagnosis of CS [5,6]. Rapini et al reported eleven patients with solitary lesions without clinical evidence of this genodermatosis [7].…”

“…Histopathologically, storiform collagenoma is a wellcircumscribed but unencapsulated, hypocellular dermal proliferation, composed of hyalinized collagen bundles arranged in a whorled or plywoodlike pattern, separated by clefts [6,12]. Immunohistochemical stains are positive for vimentin, focally positive for CD34, and factor XIIIa…”

“…Dermatology Online Journal || Photo Vignette [2,6]. Electron microscopy reveals collagen fibrils of 40-50nm in diameter interspersed with electrodense parallel linear structures; these collagen fibrils also show cross striations that appear approximately every 70nm [15].…”